Go add twittersearch as a follower, wait one minute, then send a direct message to twittersearch with a search query (“d twittersearch foo”). You should get a direct message back within a minute from Dave Troy’s wonderful Twitter Search hack with the last public update matching your search query.
Why? Because I can. 173 lines of Ruby glue code. Are you ready for Twitter web services This is the start of something very interesting.
UPDATE: Of course, right when I launch this thing, Twitter vanishes from the internets. My guess: the tubes are full.